A YubiKey is a small hardware device that offers two-factor authentication with a simple touch of a button. YubiKeys are built strong enough for the largest enterprises, while remaining simple enough for anyone to use. The YubiKey NEO offers both contact (USB) and contactless (NFC, MIFARE) communications. YubiKeys support FIDO U2F, Yubico-OTP, OATH-OTP, OATH-HOTP, OATH-TOTP, OpenPGP, and PIV, and one security key can support an unlimited number of applications without the need for drivers, client software, or batteries. To learn more about the YubiKey, see YubiKey Hardware.